Charts for permanent displacement-based seismic design of cantilever retaining walls

Abstract

This study proposes seismic design charts to predict the permanent displacements in cantilever retaining walls. These charts are developed considering the realistic v-shaped mechanism in the backfill. It captures the aleatory uncertainty of earthquake motions by incorporating numerical analysis results for 152 earthquake ground motions. Conventionally, the charts developed for slopes and gravity walls have been adopted by practitioners for cantilever retaining walls assuming an imaginary vertical plane through the wall heel and considering the soil above as a part of the wall itself. Using these conventional charts of slopes with a single wedge assumption may lead to misleading predictions, which is one of the motivations behind developing charts specifically for the cantilever retaining walls. It also provides an estimation for the resulting subsidence in the backfill that may induce distress in the overlying structures. Unlike conventional charts, 5% - 20% probability of exceedance curves besides upper-bound curves have been developed accounting for earthquake motion variability. Non-dimensional equations have been proposed to estimate the minimum heel-length of the wall with and without shear key for the design values of PGA and PGV.